PwC managing partner, Brian Cullinan, handed presenters Faye Dunaway and Warren Beatty the wrong envelope as they walked on stage, which led to "La La Land" mistakenly being named best picture instead of actual winner "Moonlight."

How Cullinan mixed up the envelopes remains unclear, as does why it took more than two minutes for the error to be corrected.

The accountants

While Beatty and Dunaway were presenting the award on stage, Cullinan tweeted a photo of Emma Stone he had taken after she won with the caption "Best Actress Emma Stone backstage!" He would later delete the tweet, but not before some social media users had screen grabbed it.

On Wednesday, Variety published photos of Cullinan backstage taken moments before the best picture announcement. In the photos, Cullinan is seen holding two envelopes and a phone in his hand, moments before Beatty and Dunaway walked onstage.

PwC has not said whether Cullinan's tweets distracted him from his responsibilities and Cullinan has not commented publicly on the incident.

A self-described Matt Damon look-alike, Cullinan is the lead partner for the Academy of Motion Picture Arts and Sciences and its annual balloting for the Academy Awards.

He became a partner with the firm in 1997, according to his Linkedin profile.

A source familiar with Cullinan's background said he is well liked and highly regarded within the ranks of PwC.

Ruiz is also a PwC veteran of nearly 20 years. She joined the firm's Academy ballot team in 2015.

According to a description of its Oscar protocol on the PwC website, Cullinan and Ruiz memorize each winner and prepare two briefcases -- each with a complete set of envelopes bearing all the Oscar winners' names. The two stand on opposite sides of the stage and alternate distributing the envelopes to the presenters.

The Academy

The Academy has largely left explaining Sunday's best picture flub to PwC.

Its first public statement on the matter came nearly 24-hours after the show. By that time, PwC had already taken "full responsibility" for the fiasco.

"Everyone was a little shaken. Everybody looked white-faced and the blood was just drained from [them]," he said.

The Oscars production team does not handle the envelopes, but, still, DeLuca said he was "heartbroken" by how the show ended.

DeLuca added that he and co-producer Jennifer Todd were not going to rush the show's end after the best picture announcement, even though it was already running long.

"There was no way we were going to not allow the 'Moonlight' team to have their moment, so we said, 'Let it ride. At least we can correct the mistake,' to the extent that the 'Moonlight' people would be able to get up there and say something."

What's next?

After years of scrutiny regarding the lack of diversity in the Academy's voting ranks -- and its ongoing efforts to change that -- "envelopegate" has so far overshadowed the significance of "Moonlight's" win -- a film by and about African Americans.

In a few months, the film festival circuit begins again -- along with buzz for the next crop of Oscar contenders. For the Academy, a new storyline undoubtedly can't come soon enough.

As for PwC, the Academy is only a small part of the firm's global business. It employs 223,000 people and had sales of $39.5 billion last year.

Whoever carries the Oscar ballots to the next Academy Awards, it's probably safe to assume they won't also be carrying phones.